261442469 has 2 divisors, whose sum is σ = 261442470. Its totient is φ = 261442468.

The previous prime is 261442421. The next prime is 261442471. The reversal of 261442469 is 964244162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 258019969 + 3422500 = 16063^2 + 1850^2 .

It is a cyclic number.

It is not a de Polignac number, because 261442469 - 2⁸ = 261442213 is a prime.

It is a super-2 number, since 2×261442469² = 136704329193631922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 261442471, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261441469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130721234 + 130721235.

It is an arithmetic number, because the mean of its divisors is an integer number (130721235).

Almost surely, 2^261442469 is an apocalyptic number.

It is an amenable number.

261442469 is a deficient number, since it is larger than the sum of its proper divisors (1).

261442469 is an equidigital number, since it uses as much as digits as its factorization.

261442469 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 38.

The square root of 261442469 is about 16169.1826942490. The cubic root of 261442469 is about 639.4285825783.

The spelling of 261442469 in words is "two hundred sixty-one million, four hundred forty-two thousand, four hundred sixty-nine".